Heretofore, there has been no capability to accurately and timely predict earthquakes. The preponderance of private, university, and government research monies dedicated to earthquakes have been expended on seismological studies, with only negligible funding of alternative concepts. The seismological work has focused on statistical predictions and understanding of seismic and geological process. Those types of statistics have resulted in forecasts such as “a magnitude 7 earthquake is likely to occur within the next decade in Southern California.” Predictions of that nature are of little practical value in terms of human activity: there is no inducement to evacuate buildings based on that kind of prediction. Predictions of incipient earthquakes, which are more than a few days or tens of hours in the future are rightly ignored. Conversely, predictions, which provide scant seconds, also preclude effective response. To be truly useful for preservation of life and property, predictions must have several features:
(1) Geo-positional precision. That is, a prediction must forecast the latitude and longitude of the forthcoming event with sufficient accuracy so that economically efficient response is realizable. It is wasteful to forecast an earthquake for “Southern California” if the forecast could be further refined to “the region centered on a specific locale, and the area around that locale to a distance of 5 kilometers.” The latter forecast can be acted upon. An invocation to evacuate Southern California cannot.
(2) Temporal accuracy. There is little or no utility in forecasting an earthquake to occur in weeks or months, or in seconds. Humanity responds to warnings of days, hours, and minutes—outside those parameters predictions lose practical utility.
(3) Accurate prediction of magnitude of the incipient earthquake. Earthquakes over magnitude 5 are inherently dangerous to persons and property.
(4) Low false alarm rate and a correlatively high probability of accurate prediction. False alarms are counter-productive. There must be a high probability of accurate prediction, with a commensurately low false alarm rate. If predictions are made for earthquakes to occur with a weekly frequency, the predictions will be wrong most of the time, and the public will be dissuaded from responding to the frequent errors in prediction.
(5) Reliable, sustainable, and realistic physics-based predictions. The use of barking dogs, nervous cats, falling water levels in wells, and other sporadic phenomena are often cited as good indicators of an impending earthquake. None of those techniques (and many others) could be construed as reliable methods for earthquake prediction. A viable earthquake prediction system must be commensurate with trust, based on demonstrated success, reliable operation, and a foundation in physics.
As is discussed further below, embodiments of the present invention are based principally on the use of radio-tomographic techniques to discriminate earthquake pre-cursors, which manifest themselves in the ionosphere and atmosphere. In particular, noticeable changes (most often - reduction) in the electron density occur in ionospheric regions above an area where an earthquake is imminent. These often appear a few days before the event occurs. Uniqueness of particular irregularities in electron density and turbulence in the ionosphere above the earthquake's eventual epicenter, as well as other ionospheric phenomena appear. Such observations have been made by ionosondes, satellites, and other experimental means, none of which are capable of spatially imaging the electron density distribution.
Based on such data it is impossible to divorce the ionospheric effect of earthquake preparation processes from a multitude of “natural” non-seismic processes in the ionosphere, such as those processes caused by the influence of the sun and cosmic effects. Ionosondes are incapable of discerning the fine spatio-temporal structures in the ionosphere, which uniquely identify earthquake-precursor-related anomalies. A method of the present invention uses three-dimensional (“3D”) and two-dimensional (“2D”) tomographic images, which makes it possible to study the spatial structure of ionospheric disturbances and to separate the ionospheric effects of earthquake preparation from other solar and terrestrial influences. Prior techniques all fail to do this, and thus fail to deliver viable earthquake prediction capabilities.